Additive Manufacturing of Curved SiO2-Based LTCC with Regulated Curing Behavior and Geometry-Preserving Sintering

The growing demand for conformal microwave devices in aerospace and autonomous systems requires ceramic substrates with low dielectric loss and curved geometries. While low-temperature co-fired ceramics (LTCC) are ideal candidates for such high-frequency applications, their conventional manufacturing is mainly limited to planar structures. In this work, an integrated digital light processing (DLP) strategy for manufacturing curved SiO 2 -based LTCC components was developed to address the key challenges of slurry rheology, curing behavior, and sintering-induced deformation. First, a 1.0 wt.% KH-570 modification was used to enhance the powder-resin interface through Si-O-Si bonding and polymerizable functional groups, yielding a printable slurry (50 vol.% loading, 2.74 Pa·s at 30 s –1 ). Second, to mitigate excessive light penetration in the low-scattering SiO 2 system, a UV absorber was incorporated to regulate the curing behavior, reducing the penetration depth ( D p ) from 96.3 μm to 52.0 μm. Third, a buried powder sintering strategy was implemented to suppress the deformation of unsupported curved architectures. Consequently, curved LTCC substrates exhibited a low dielectric constant of 2.55 and a low dielectric loss of 0.0022 at 10 GHz. The practical applicability was validated by an inkjet-printed conformal X-band microstrip antenna, which exhibited a resonant frequency of 10.11 GHz and a return loss of –25.8 dB. This work establishes an effective strategy for the additive manufacturing of curved LTCC ceramics and provides a viable route toward high-performance conformal RF devices.